Here's how to do it.
Download and install to Windows 7 the Partition Wizard Home program from this link below. Partition Wizard Free Home Edition
Then use the outline in these snips to resize the Windows 7 C: partition to create unallocated space that the F: partition can then be resized into.
My Test 1 G: - equales your Windows 7 C:
My Test 2 H: - equales your J F:
click an image to enlarge